1. Field of the Invention
The present invention relates to a perpendicular magnetic write head performing a writing process of perpendicular magnetic writing method and a method of manufacturing the same, and a magnetic write device equipped with such a perpendicular magnetic write head.
2. Description of the Related Art
In recent years, with improvement of the areal recording density of a magnetic recording medium (hereinafter, simply referred to as a “recording medium”) such as a hard disk, performance improvement is desirable in a thin film magnetic head equipped on a magnetic write device such as a hard disk drive. As a writing method of the thin film magnetic head, there is known a longitudinal writing method setting a direction of a signal magnetic field in an in-plane direction (longitudinal direction) of the recording medium. There is also known a perpendicular writing method setting the direction of the signal magnetic field in the direction intersecting a surface of the recording medium. The longitudinal writing method has been widely used today. However, in consideration of the market trend with the improvement of the areal recording density, the perpendicular writing method is envisaged to be promising instead of the longitudinal writing method. This is because, in the perpendicular writing method, such advantages can be obtained that a liner recording density is increased, and further that the recording medium which has been subjected to recording is hardly influenced by a thermal fluctuation.
The thin film magnetic head of the perpendicular writing method (hereinafter, referred to as a “perpendicular magnetic write head”) is provided with a thin film coil generating a magnetic flux for writing, and a main magnetic pole layer leading the magnetic flux generated in the thin film coil to the recording medium. According to the perpendicular magnetic write head, the recording medium is magnetized by the magnetic field generated by the magnetic flux for writing (the perpendicular magnetic field); thereby information is magnetically recorded on the recording medium.
As the perpendicular magnetic write head, there is known the perpendicular magnetic write head provided with the main magnetic pole layer extending in the direction intersecting an air bearing surface. This type of the perpendicular magnetic write head is generally referred to as a “single magnetic pole type head”. As a specific structure of the single magnetic pole type head, there is known the structure that an auxiliary magnetic pole layer is located adjacent to the main magnetic pole layer so as to increase the intensity of a perpendicular magnetic field. (For example, refer to Japanese Unexamined Patent Publication No. Hei-02-066710 and Japanese Unexamined Patent Publication No. 2002-197615). However, it is said that the single magnetic pole type head has a limitation to improve the recording density of the recording medium.
Thus, in recent years, in order to achieve the improvement in the recording density, the perpendicular magnetic write head with a write shield layer is entering the mainstream. The write shield layer is for absorbing the spread component of the magnetic flux released from the main magnetic pole layer, and is located away from the main magnetic pole layer with a gap layer in between. This type of the perpendicular magnetic write head is generally referred to as a “shield type head”. As a specific structure of the shield type head, there is known the structure that the write shield layer is disposed on the trailing side of the main magnetic pole layer (for example, refer to Japanese Unexamined Patent Publication No. 2001-250204 and European Patent Publication No. 0360978)
In particular, as the structure of the shield type head, there is known the structure that the auxiliary magnetic pole layer is provided on the trailing side of the main magnetic pole layer so as to suppress the unintentional erase of the information recorded on the recording medium during writing process (for example, refer to Japanese Unexamined Patent Publication No. 2006-155866).